Gas canisters and methods for making them

ABSTRACT

Canisters are provided that include a cylindrical body and a cap welded to the body to define a cavity filled with carbon dioxide or other fluid. The canisters may be loaded into a medical device, e.g., to provide an energy source for operating the device. Methods for making such canisters are also provided.

RELATED APPLICATION DATA

The present application is a continuation-in-part of co-pending U.S.application Ser. No. 15/064,464, filed Mar. 8, 2016, issuing as U.S.Pat. No. 10,610,351, the entire disclosure of which is expresslyincorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates generally to canisters for storing gases,and, more particularly, to single-use gas canisters that may be loadedinto a medical device or other tool for providing energy during use ofthe medical device or other tool, and to methods for making suchcanisters.

BACKGROUND

Various surgical procedures involve the use of medical devices thatrequire an energy source, e.g., to provide a discharge force tocomponents of the devices. For example, an intraocular lens inserterdevice may be used to deliver a replacement lens within an eye sufferingfrom a cataract. Such an IOL inserter may require an external powersource to push a lens loaded into the inserter into a patient's eye.

Accordingly, energy sources for IOL inserters and other medical devicesor tools would be useful.

SUMMARY

The present disclosure is directed to canisters for storing gases, and,more particularly, to single-use gas canisters that may be loaded into amedical device or other tool for providing energy during use of themedical device or other tool, and to methods for making such canisters.

In accordance with an exemplary embodiment, a canister is provided thatincludes an elongate, e.g., cylindrical, body and a cap attached to thebody to define a cavity filled with gas, e.g., pressurized and/or atleast partially liquefied carbon dioxide. In some embodiments, the bodyincludes a barrel region defining a first diameter, an enclosed firstend, and a neck region, optionally defining a second diameter smallerthan the first diameter, and extending from the barrel region to an opensecond end defining an end wall, the body defining a central axisextending between the first end and the second end. The cap may includean annular portion including a closed first end an open second end, apenetrable or separable septum formed in the first end, and an annularflange extending radially from the second end of the annular portion,thereby defining a lower surface defining a plane substantiallyperpendicular to the central axis, and an annular projection extendingfrom the lower surface.

In an exemplary embodiment, the first end of the annular portion may beinserted into the open second end of the body of the canister such thatthe annular portion is spaced from an interior surface of the neckregion and the septum is disposed within the neck region, and theprojection may be welded to the end wall of the second end of the body,thereby enclosing the cavity.

In accordance with another embodiment, a gas-actuated tool is providedthat includes a housing comprising a functional portion and an actuatorportion including a chamber; a canister within the chamber comprising anelongate body comprising an enclosed first end and an open second end, acap welded to the open second end of the elongate body and including aseptum, thereby defining an interior cavity filled with pressurized gas,the septum comprising a central region and a relatively-thin perimeterat least partially surrounding the central region; and a carriagemovable within the housing from the first position, the carriagecomprising a pin disposed adjacent the septum, the pin including ablunt, beveled tip. An actuator on the actuator portion is coupled tothe carriage such that initial activation of the actuator causes thecarriage to move from the first position to a second position such thatthe beveled tip of the pin applies localized force to the septum to atleast partially separate the septum from the cap, thereby releasingpressurized gas from the canister into one or more passages within thehousing.

In accordance with another embodiment, a method is provided for making acanister that includes providing an elongate, e.g., cylindrical, bodycomprising a barrel region defining a first diameter, an enclosed firstend, and a neck region defining a second diameter smaller than the firstdiameter and extending from the barrel region to an open second enddefining an annular end wall, the body defining a central axis extendingbetween the first end and the second end; and providing a cap comprisingan annular portion including a closed first end and an open second end,a penetrable or separable septum formed in the first end, and an annularflange extending radially from the second end of the annular portion,thereby defining a lower surface defining a plane substantiallyperpendicular to the central axis, and an annular projection extendingfrom the lower surface. The first end of the annular portion may beinserted into the open second end of the body of the canister such thatthe annular portion is spaced from an interior surface of the neckregion and the septum is disposed within the neck region. Gas, e.g.,carbon dioxide, nitrogen, or hydrofluorocarbon, may be introduced intoan interior of the body, and the projection may be welded to the endwall of the second end of the body, thereby enclosing a cavity of thecanister with the gas therein.

Alternatively, the cap (including a separable septum) may include anouter flange that is larger than the open second end of the body.Instead of inserting the cap into the open second end, the flange may bepositioned over the open second end and welded to the neck region.

In accordance with yet another embodiment, a method is provided forpreparing a medical device or other tool for a procedure that includesproviding a device comprising a housing including a chamber with acanister therein, an actuator, and a carriage in a first position withinthe housing, the canister comprising an elongate body comprising anenclosed first end and an open second end, a cap welded to the opensecond end including a septum, thereby defining an interior cavityfilled with pressurized and/or at least partially liquefied gas; andactuating the actuator to cause the carriage to move from the firstposition to a second position such that a pin on the carriage opens theseptum, thereby releasing pressurized gas from the canister into one ormore passages within the device. In one embodiment, the septum may be arelatively thin-walled panel that may be penetrated or punctured by thepin to open the cap. In another embodiment, the septum may include arelatively thin perimeter surrounding a relatively thick central portionsuch that, the pin causes at least a portion of the perimeter to tearotherwise separate to open the cap.

In accordance with still another embodiment, a method is provided forpreparing a medical device or other tool for a procedure that includesproviding a canister comprising an elongate body comprising an enclosedfirst end and an open second end, a cap welded to the open second endincluding a septum, thereby defining an interior cavity filled withpressurized and/or at least partially liquefied gas; loading thecanister into a housing of a device; and actuating the device to cause apin in the housing to open the septum, thereby releasing pressurized gasfrom the canister into one or more passages within the device.

In accordance with another embodiment, a method is provided forperforming a procedure that includes providing a medical devicecomprising a housing including a chamber with a canister therein, anactuator, and a carriage in a first position within the housing, thecanister comprising an elongate body comprising an enclosed first endand an open second end, a cap welded to the open second end including aseptum, thereby defining an interior cavity filled with pressurizedand/or at least partially liquefied gas; initially actuating theactuator to cause the carriage to move from the first position to asecond position such that a pin on the carriage opens the septum,thereby releasing pressurized gas from the canister into one or morepassages within the medical device to pressurize an incompressibleliquid within the housing; and subsequently actuating the actuator,thereby causing the incompressible liquid to flow and deliver one of anagent and an implant from the medical device into a patient.

In accordance with still another embodiment, a medical device isprovided that includes a housing comprising a treatment portion and anactuator portion including a chamber; a canister within the chambercomprising an elongate body comprising an enclosed first end and an opensecond end, a cap welded to the open second end and including apenetrable or separable septum, thereby defining an interior cavityfilled with pressurized gas; a carriage movable within the housing fromthe first position, the carriage comprising a pin disposed adjacent theseptum; and an actuator on the actuator portion coupled to the carriagesuch that initial activation of the actuator causes the carriage to movefrom the first position to a second position such that the pin opens theseptum, thereby releasing pressurized gas from the canister into one ormore passages within the medical device.

In accordance with yet another embodiment, a gas-powered tool isprovided that includes a housing comprising a functional portion and anactuator portion including a chamber; a canister within the chambercomprising an elongate body comprising an enclosed first end and an opensecond end, a cap welded to the open second end and including apenetrable or separable septum, thereby defining an interior cavityfilled with pressurized and/or at least partially liquefied gas; acarriage movable within the housing from the first position, thecarriage comprising a pin disposed adjacent the septum; and an actuatoron the actuator portion coupled to the carriage such that initialactivation of the actuator causes the carriage to move from the firstposition to a second position such that the pin opens the septum,thereby releasing pressurized gas from the canister into one or morepassages within the tool.

In an exemplary embodiment, the pin may include a blunt, e.g., beveled,tip that may be sized to open the septum. For example, a beveled tip mayapply a more localized force to the septum, which may reduce the overallforce needed to open the septum. The pin may have a diameter or othercross-section smaller than the septum, e.g., to allow gas to flow freelyand/or quickly around the pin once the septum is opened.

Other aspects and features including the need for and use of the presentdisclosure will become apparent from consideration of the followingdescription taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

It will be appreciated that the exemplary apparatus and componentsthereof shown in the drawings are not necessarily drawn to scale, withemphasis instead being placed on illustrating the various aspects andfeatures of the illustrated embodiments. The drawings illustrateexemplary embodiments, in which:

FIG. 1A is a cross-sectional view of an exemplary embodiment of anintraocular lens inserter including a single-use gas canister loadedtherein.

FIG. 1B is a cross-sectional view of the lens inserter of FIG. 1A withan actuator activated such that a pin punctures a septum of the gascanister to deliver gas therefrom for providing an energy source for thelens inserter.

FIG. 1C is a detail showing an exemplary embodiment of a pin on anactuator, such as that shown in FIGS. 1A and 1B, which may be used topuncture the septum of a gas canister, such as that shown in FIGS. 5Aand 5B.

FIG. 2 is a cross-sectional view of an exemplary embodiment of a gascanister including a cap welded to a body.

FIG. 3 is a cross-sectional detail of the body of the canister of FIG.2.

FIGS. 4A and 4B are perspective and cross-sectional views of the cap ofthe canister of FIG. 2.

FIGS. 5A and 5B are perspective and cross-sectional views of anotherembodiment of a cap.

FIG. 6 is a cross-sectional detail showing the cap of FIGS. 5A and 5Bbeing attached to the neck of a body, such as the body of FIG. 3.

FIGS. 7A and 7B are perspective views of yet another embodiment of acap.

FIG. 7C is a cross-sectional view of the cap of FIGS. 7A and 7B.

FIG. 8 is a cross-sectional view showing the cap of FIGS. 7A-7C attachedto the neck of a body to provide a gas canister.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Turning to the drawings, FIGS. 1A and 1B show an exemplary embodiment ofintraocular lens (IOL) inserter 10 that includes a lens delivery portion20, an actuator 30, and an energy device, e.g., canister 40. Theintraocular lens inserter 10 may include a main body portion 12, whichincludes various cavities, recesses, and conduits, e.g., for providingcommunication between the canister 40 and the lens delivery portion 20,e.g., for delivering a lens (not shown) from a lens compartment 22loaded into or onto, secured to, or otherwise forming a part of the lensdelivery portion 20, e.g., as described in U.S. Publication No.2015/0282928, the entire disclosure of which is expressly incorporatedby reference herein. Alternatively, the actuator 30 and energy device,e.g., canister 40, may be provided in other medical devices or tools,which may be actuated by releasing pressurized gas from the canister 40to actuate a functional portion of the tool, similar to the methodsdescribed elsewhere herein. For example, the actuator 30 and canister 40may be provided in a shunt inserter for glaucoma procedures, a syringeplunger pusher for liquid injections, or other tools (not shown).

For example, in the exemplary embodiment shown in FIGS. 1A and 1B, theIOL inserter 10 may be provided with a canister 40 already providedwithin the housing 12, i.e., secured within chamber 16. Alternatively,the housing 12 may include a removable cap 14 allowing the canister 40to be removed and replaced with a new canister, if desired. In theembodiment shown, the IOL inserter 10 includes a carriage 32 coupled tothe actuator 30 and carrying a pin 34. When the canister 40 is loadedinto the chamber 16 (e.g., during manufacturing or before use, such as,for example, where the canister 40 may be loaded into the housing 12 viathe cap 14 sometime prior to use), the pin 34 may be disposed adjacent aseptum 67 of the canister 40, as shown in FIG. 1A. In addition, the IOLinserter 10 may include an O-ring or other seal 36 disposed within thechamber 16 adjacent the pin 34, which may slidably engage a neck 58 ofthe canister 40, e.g., to provide a substantially fluid-tight sealbetween the neck 58 and the fluid passages within the IOL inserter 10.

Optionally, the carriage 32 may be slidably disposed within the mainbody portion 12, e.g., such that activation of the actuator 30, as shownin FIG. 1B, causes the carriage 32 and pin 34 to move axially, e.g.,from the original or distal position shown in FIG. 1A proximally towardsthe canister 40 to the proximal position shown in FIG. 1B, therebypuncturing the septum 67 with the pin 34 and allowing gas to escape fromthe canister 40. Optionally, a spring or other biasing mechanism 38 maybe provided within the main body portion 12, e.g., within the chamber 16adjacent the O-ring 36 and/or around the neck 58 of the canister 40, forbiasing the carriage 32 distally towards the distal position. Thus, whenthe actuator 30 is released, the carriage 32 may automatically return tothe distal position and the pin 34 may be withdrawn from the septum 67,as shown in FIG. 1A. For example, FIG. 1C shows a pin 34 that may becoupled to the actuator 30 to press the septum 167 shown in FIGS. 5A and5C inwardly to cause the perimeter 167 b to at tear or otherwiseseparate at least partially between the central region 167 a and theshoulder to open the canister 40.

For example, FIG. 1C shows an exemplary embodiment of a pin 34 that maybe carried by the actuator 30 (not shown in FIG. 1C). In thisembodiment, the pin 34 includes a blunt, e.g., beveled tip 34 a that maybe sized to open a canister 40. For example, a beveled tip 34 a mayapply a more localized force to a septum 167 of the canister 40 (e.g.,the septum 167 shown in FIGS. 5A and 5B and described further elsewhereherein), which may reduce the overall force needed to open the septum167, as described further elsewhere herein. The pin 34 may have adiameter or other cross-section smaller than the septum 167, e.g., toallow gas to flow freely and/or quickly around the pin 34 once theseptum 167 is opened, as described elsewhere herein.

In some instances, the lens compartment 22 may be a lens cartridge thatmay be loaded into the lens delivery portion 20. In other instances, thelens compartment 22 may be fixedly attached to or form an integral partof the IOL inserter 10. The IOL inserter 10 may be used to deliver alens contained within the lens compartment 22 into a patient's eye. Forexample, the actuator 30 may be activated to deliver gas from thecanister 40 through one or more passages of the main body portion 12,e.g., to pressurize an incompressible fluid to deliver the lens from thelens delivery portion 20 during a cataract surgical procedure.

Turning to FIG. 2, an exemplary embodiment of a canister 40 is shown. Insome instances, the canister 40 may provide a single-use energy sourcefor a medical device or other tool, such as the IOL inserter 10 of FIGS.1A and 1B. Generally, the canister 40 includes a body 50 and a cap 60welded to the body 50 to provide an enclosed cavity 42 filled with afluid, e.g., carbon dioxide. The fluid contained within the enclosedcavity 42 may be used to provide a desired potential energy or dischargeforce to the IOL inserter 10, e.g., to advance the lens from the lensdelivery portion 20. In alternative embodiments, the canister 40 may befilled with other two-phase gases, such as a hydrofluorocarbon (e.g.,HFC-134a), or a single-phase gas, such as nitrogen. As used herein,“pressurized gas” may include a single-phase gas or a two-phase gas,e.g., in which the gas has been at least partially liquefied, and so mayinclude either a gaseous or mixed liquid-gaseous state fluid. The volumeof the cavity 42 may be sufficient to provide energy to the medicaldevice, e.g., a discharge force for the IOL inserter 10 that may besubstantially constant and/or controlled when the actuator 30 isactuated. In an exemplary embodiment, the cavity 42 may have an interiorvolume of no more than about 1.8 milliliters (1.8 mL), or not more thanabout one milliliter (1 mL), e.g., between about 0.5-1.8 mL, or betweenabout 0.68-0.75 mL. However, in other embodiments, the interior volumeof the cavity 42 may be any desired volume. For example, in someinstances, the interior volume of the cavity 42 may be greater than 1.8mL or less than 0.5 mL.

In some embodiments, the body 50 and cap 60 are formed from stainlesssteel or other corrosion resistant, desired, or suitable metal, or othermaterial. In some embodiments, one or more of the body 50 and cap 60 maybe formed by one or more of drawing, stamping, machining, casting,molding, and the like. For example, with reference to FIG. 3, the body50 may be deep drawn from sheet metal, e.g., a round sheet metal blankof Type 305 stainless steel, using one or more dies and punches (notshown), e.g., to form a main barrel region 52 and enclosed base or firstend 54 of the body 50. Additional processing may be used to form atapered shoulder region 56 and open neck region or second end 58defining an opening or passage 59 communicating with an interior 51 ofthe body 50. For example, the shoulder and neck regions 56, 58 may beformed by necking and the like, such that the neck region 58 has asubstantially uniform diameter smaller than the diameter of the mainbarrel region 52. Alternatively, the neck region 58 may have a diametersimilar to the main barrel region 52, i.e., omitting the shoulder region56. The regions of the body 50 may be substantially radially symmetricalabout a central axis 44 of the canister 40. The neck region 58 mayterminate in a substantially planar end wall 58 a defining a planesubstantially perpendicular to the axis 44.

In an exemplary embodiment, the body 50 may have a length between thefirst end 54 and the end wall 58 a of the neck region 58 that is lessthan about thirty millimeters (30 mm), the outer diameter of the barrelregion 52 may be not more than about ten millimeters (10 mm) or not morethan about eight millimeters (8 mm), and the outer diameter of the neckregion 58 may be not more than about five millimeters (5 mm), or notmore than about four millimeters (4 mm). The neck region 58 may have asubstantially uniform diameter length between about three to eightmillimeters (3-8 mm) or between about four to six millimeters (4-6 mm),e.g., having sufficient length to accommodate the O-ring 36 and carriage32 sliding along the neck region 58 during actuation of the IOL inserter10, as described elsewhere herein. However, the provided dimensions andshapes are merely examples. Thus, the various dimensions of the variousaspects of the canister 40 may be selected to be any desired dimension.Further, the shapes of the various aspects of the canister may be anydesired shape. For example, one or more shapes of one or more aspects ofthe canister may be radially asymmetrical relative to the central axis44 of the canister 40.

Similarly, as best seen in FIGS. 4A and 4B, the cap 60 may be stamped,coined, drawn, and/or otherwise processed from another blank, e.g., todefine an annular body 62 having a relatively thin closed or first end64 and an open second end 66 also symmetrical about the axis 44. Theannular body 62 may have an outer diameter smaller than the neck region58 of the body 50 such that the annular body 62 may be inserted into theopening 59 while providing a desired clearance between the annular body62 and the neck region 58, which facilitates projection welding the cap60 to the body 50, as described elsewhere herein.

The closed end 64 is formed to include a penetrable wall or septum 67having a desired diameter and/or thickness for accessing the gas withinthe cavity 42 once the canister 40 is loaded into a medical device, asdescribed further elsewhere herein. In an exemplary embodiment, theseptum 67 may have a substantially uniform thickness. For example, insome embodiments, the septum 67 may have a wall thickness between about0.10-0.25 mm. In other embodiments, the septum 67 may have a wallthickness of not more than about 0.16 mm. In some embodiments, theseptum 67 may have a diameter between about 0.80-1.20 mm. In otherembodiments, the septum 67 may have a diameter of not more than about1.0 mm. Although some exemplary dimensions are provided, the scope ofthe disclosure is not so limited. Rather, the dimensions and shapes ofvarious aspects of the cap 60 may be any desired shape or dimension. Forexample, the various dimensions and shapes of the cap 60 may be selectedbased on the application of the cap 60 and/or canister 40.

The septum 67 may be surrounded by thicker shoulder 68 to support theseptum 67 while allowing the septum 67 to be penetrated during operationof a medical device. For example, in some embodiments, the septum 67 maybe penetrated during loading of the canister 40 into a medical device.In other embodiments, the septum 67 may be penetrated some time afterinstallation of the canister 40 into the medical device, such as, forexample, during actuation of the medical device. For example, the septum67 may be sized to engage the pin 34 of the IOL inserter 10 shown inFIG. 1B when the canister 40 is loaded into the chamber 16 of the IOLinserter 10 such that the pin 34 easily punctures the septum 67 with adesired maximum puncture force when the actuator 30 is first activated.In some embodiments, the force needed to puncture the septum 67 may benot more than about one hundred Newtons (100 N). In some embodiments,the force needed to puncture the septum 67 may be not more than abouteighty Newtons (80 N). However, the force needed to puncture the septum67 may be selected to be any desired force. Thus, in some embodiments,the puncture force may be greater than eighty Newtons (80 N) or greaterthan one hundred Newtons (100 N). Upon puncture of the septum 67, thegas within the canister 40 is controllably released during use of theIOL inserter 10, as described elsewhere herein.

Alternatively, as shown in FIG. 1C, the septum 167 may be a generallycircular disc or panel defining a first thickness surrounded by arelatively thin-walled perimeter 167 b extending to the shoulder 168,e.g., similar to the septum 167 shown in FIGS. 5A and 5B describedelsewhere herein. The thickness of the perimeter 167 b may be selectedto facilitate separation of the septum 167 at least partially from theshoulder 168 when a predetermined puncture force is applied to theseptum 167, e.g., not more than about eighty Newtons (80 N) or otherwisesimilar to the other embodiments described elsewhere herein.

The second end 66 of the cap 60 includes an annular flange 69 extendingradially outwardly relative to the annular body 62, e.g., substantiallyperpendicular to the axis 44, thereby defining a lower surface 69 aadjacent the annular body 62 and an upper surface 69 b opposite thelower surface 69 a. The lower surface 69 a may be substantially planarand may include an annular projection 70 that is spaced apart from theannular body 62 and from an outer edge 69 c of the annular flange 69. Insome embodiments, the projection 70 may extend entirely around theannular body 62 along the lower surface 69 a. In some embodiments, theprojection 70 may be continuous. In other embodiments, the projection 70may be discontinuous. In an exemplary embodiment, the projection 70 maytaper from the lower surface 69 a and terminate in a substantiallyplanar end surface 70 a, e.g., having a height between about 0.2-0.3 mm,e.g., about 0.25 mm. Alternatively, as shown in FIG. 6, the projection70 may be omitted and the lower surface 169 a of the annular flange 160may be positioned immediately against the end wall 58 a of the neckregion 58, as described elsewhere herein.

Once formed, the body 50 and cap 60 may be further processed, e.g.,deburred, have sharp edges broken, and the like, to provide, forexample, a desired finish for the components before assembly.

The cap 60 may be substantially permanently attached to the body 50,e.g., by projection welding. For example, in an exemplary process, thebody 50 and cap 60 may be placed in a filling chamber (not shown) andthe filling chamber may be filled with carbon dioxide (or other gas) toa desired pressure, thereby filling the interior 51 of the body 50 withthe CO2. The filling chamber may be controlled to a desired temperaturesuch that it is below the saturation temperature of the gas at fillingpressure to condense the gas in the canister 40, thus filling thecanister 40 with liquefied gas.

Once filled, the cap 60 may be welded to the neck region 58 to close theinterior 51 and seal the liquid CO2 within the resulting canister 40.For example, the first end 64 of the annular body 62 may inserted intothe passage 59 in the neck region 58 such that the wall of the annularbody 62 is spaced apart from the inner surface of the neck region 58,e.g., until the end surface 70 a of the projection 70 contacts the endwall 58 a of the neck region 58. In this manner, when the cap 60 iswelded to the body 50, the resulting weld may be formed between theprojection 70 and the end wall 58 a of the neck region 58. For example,in an exemplary projection welding procedure, the body 50 may be coupledto ground (or one electrode) within the filling chamber and an oppositeelectrode may be placed against the upper surface 69 b of the annularflange 69 on the cap 60, thereby holding the projection 70 against theend wall 58 a of the neck region 58. Once the body 50 and cap 60 areengaged, electrical energy may be applied to the electrode, therebyforming a weld to attach the cap 60 and seal the resulting cavity 42 ofthe canister 40 with a desired volume of liquid CO2 therein.

In another alternative, instead of the annular body 62, the septum maybe formed within the same plane as the annular flange 69, which may havean outer diameter that is larger than the neck region 58 of the body 50,and an outer lip or flange may be provided (not shown) around theannular flange 69 sized to be received over the neck region 58. In thisalternative, instead of inserting the annular body of the cap into theopen second end, the outer lip or flange may be positioned over the opensecond end and welded to the neck region 58, e.g., similar to a bottlecap, except including a separable septum, such as any of the embodimentsdescribed herein.

When the canister 40 is removed from the filling chamber, the CO2 mayreturn to its gaseous state or a mixed liquid-gaseous state, therebyproviding a desired pressure within the cavity 42. In an exemplaryembodiment, the mass of CO2 provided within the canister 40 afterfilling may be about six hundred milligrams (600 mg) or less, or aboutfive hundred milligrams (500 mg) or less and/or having a resultingdensity between about 0.50-1.0 kg/L or between about 0.50-0.75 kg/L. Instill other embodiments, the mass and/or density of the fluid, such asCO2, within the canister 40 may be selected to be any desired mass ordensity. Further, it will be appreciated that gases or fluids other thanCO2 may be used to fill the canister 40 that provide a desired pressureand/or discharge force during use, as desired.

Turning to FIGS. 5A and 5B, another embodiment of a cap 160 is shownthat may be formed using similar materials and methods as the cap 60,e.g., drawn from a blank to define an annular body 162 having arelatively thin closed or first end 164 and an open second end 166. Theannular body 162 may have an outer diameter smaller than the neck region58 of the body 50 such that the annular body 162 may be inserted intothe opening 59 while providing a desired clearance between the annularbody 162 and the neck region 58, which facilitates projection weldingthe cap 160 to the body 50, as described elsewhere herein.

The closed end 164 is formed to include a separable wall or septum 167having a desired diameter and/or thickness for accessing the gas withinthe cavity 42 once the canister 40 is loaded into a medical device (notshown), as described further elsewhere herein. For example, as shown inFIGS. 5A and 5B, the septum 167 may include a relatively thicker centralregion 167 a at least partially surrounded by a relatively thinperimeter 167 b. Optionally, the perimeter 167 b may completely surroundthe central region 167 a or may extend only partially around the centralregion 167 a, e.g., to provide a preferential hinge, as explainedfurther elsewhere herein. Optionally, the central region 167 a may havea dome shape, e.g., as best seen in FIG. 5B or may have a substantiallyuniform thickness that is substantially thicker than the perimeter 167b. Alternatively, the cap 160 may include a relatively thin-walledseptum 167′ similar to the cap 60, e.g., as shown in FIG. 6, or the cap60 shown in FIGS. 4A and 4B may include a thin perimeter surrounding athicker central region (not shown).

The septum 167 may be surrounded by a relatively thicker shoulder 168 tosupport the septum 167 while allowing the septum 167 to be at leastpartially separated from the shoulder 168 during operation of a medicaldevice. For example, in some embodiments, the septum 167 may be pressedinwardly to cause the perimeter 167 b, e.g., by pin 34 as shown in FIG.1C, to tear or otherwise separate at least partially between the centralregion 167 a and the shoulder during or after loading of the canister 40into a medical device, as described elsewhere herein. For example, asshown in FIG. 1C, a pin 34 may be provided that includes a beveled tip34 a, which may apply a localized force against one side of the septum167, which may enhance separation of the septum 167 at least partiallyfrom the shoulder 168. The pin 34 may have a diameter smaller than theouter perimeter of the septum 167, e.g., to facilitate gas flowingfreely from the canister 60 around the pin 34 once the septum 167 is atleast partially separated from the shoulder 168.

The second end 166 of the cap 160 includes an annular flange 169extending radially outwardly relative to the annular body 162, e.g.,substantially perpendicular to the axis 44, thereby defining a lowersurface 169 a adjacent the annular body 162 and an upper surface 169 bopposite the lower surface 169 a. The lower surface 169 a may besubstantially planar and may include an annular chamfer 170 thattransitions from the lower surface 169 a to the second end 166 of theannular body 162, e.g., to provide a welding interface for attaching thecap 160 to the body 50, as described further elsewhere herein.

Optionally, the annular body 162 may include one or more radialprojections 172, e.g., a plurality of projections 172 spaced apartaround the circumference of the second end 166. The projections 172 maybe sized to contact the inner surface of the neck region 58 immediatelyadjacent the end wall 58 a (shown in FIG. 6) to hold the cap 160stationary and/or centered on the neck region 58 during attachment. Inaddition or alternatively, the annular body 162 may include one or moregrooves or passages 174 in the outer surface of the annular body 162,e.g., a plurality of passages 174 extending between the first and secondends 164, 166, which may facilitate gas entering the interior of thecanister 40 during filling.

For example, with additional reference to FIG. 6, the first end 164 ofthe cap 160 may be inserted into the passage 59 in the neck region 58 ofthe body 50 until the flange 169 contacts the end wall 58 a of the neckregion 58. The projections 172 (not shown in FIG. 6) may hold the cap160 in place and/or center the cap 160 within the passage 59.

Similar to other methods herein, in an exemplary process, the body 50and cap 160 may be placed in a filling chamber (not shown) and thefilling chamber may be filled with carbon dioxide (or other gas) to adesired pressure, thereby filling the interior 51 of the body 50 withthe CO2. The passages 174 may facilitate the gas passing by the cap 160into the interior 51.

Once filled, the cap 160 may be welded to the neck region 58 to closethe interior 51 and seal the liquid CO2 within the resulting canister40. For example, the first end 164 of the annular body 162 may insertedinto the passage 59 in the neck region 58 such that the wall of theannular body 162 is spaced apart from the inner surface of the neckregion 58, e.g., until the lower surface 169 a of the flange 169contacts the end wall 58 a of the neck region 58. Once the body 50 andcap 160 are engaged, electrical energy may be applied to electrodes (notshown) coupled to the cap 160 and body 50, thereby forming a weld toattach the cap 160 and seal the resulting cavity 42 of the canister 40with a desired volume of liquid CO2 therein. When the cap 160 is weldedto the body 50, the chamfer 170 may localize the resulting weld to theinner perimeter of the neck region 58, provide line contact to localizeweld current to enable a consistent weld, may center the cap 160 in theneck region 58, and/or reduce flaring of the outer neck diameter.Optionally, it will be appreciated that other features may be providedon the cap 160 to create a concentrated flow of current at desiredlocations of the cap 160 and/or neck 58 to enhance resistance welding ofthe cap 160 to the neck 58.

Alternatively, a septum 167 similar to that shown in FIGS. 5A and 5B maybe formed within the same plane as the annular flange 169, which mayhave an outer diameter that is the same as or larger than the outerdiameter of the neck region 58 of the body 50, e.g., such that theannular flange 169 may be sized to be received over the end of the neckregion 58 and the annular body 162 may be received in the passage 59. Inthis alternative, instead of inserting the septum 167 into the passage69, the septum 167 may be provided substantially flush with the end ofthe neck region 58 when the flange 169 is attached to the neck region58, and the annular body 162 may extend into the passage 69. Optionally,the annular body 162 may include one or more features similar to otherembodiments herein, e.g., e.g., one or more projections to space and/orcenter the annular body 162 and/or grooves to facilitate filling thecanister (not shown).

Turning to FIGS. 7A-7C, in yet another alternative, a flat cap 260 maybe provided that is formed from a flat disc without an annular body. Inthis alternative, the cap 260 may include a septum 267 formed directlyin the flat disc, e.g., using similar materials and methods as otherembodiments herein. Consequently, as shown, the septum 267 may include arelatively thicker central region 267 a at least partially surrounded bya relatively thin perimeter 267 b, which is, in turn, surrounded by arelatively thick shoulder 268, as best seen in FIG. 7C. In thisalternative, as shown in FIG. 8, the cap 260 may have an outer diametersimilar to the outer diameter of the neck region 58 of a body such thatthe cap 260 may be placed over and welded directly to the end of theneck region 58.

Optionally, in any of these embodiments, after the canister 40 isremoved from the filling chamber, the canister 40 may be weighed toconfirm that a desired amount of gas has been loaded into the canister40. For example, the mass and pressure of the gas may be determined bycomparing the mass after filling with the original mass of the body 50and cap 60, e.g., to confirm that the mass and pressure lie withindesired tolerances. For example, it may be desirable to confirm that thepressure within the canister 40 does not exceed a desired maximumdensity (e.g., 0.75 mg/mL), which may otherwise result in the canister40 exceeding regulatory standards and/or safe pressures. Again, thedensity and/or mass of the fluid contained within the canister 40 may beany desired density or mass.

During subsequent storage of the canister 40 (e.g., during its normalshelf life before being loaded into and used with a medical device), itmay be desirable to confirm that gas has not leaked from the canister 40during its intended shelf life. For example, the canister 40 may beweighed again, e.g., at one or more desired intervals, to ensure thatthe gas has not leaked from the canister 40. Alternatively, othermethods may be used to confirm that gas remains within the canister 40,e.g., mass spectrometry and the like. For example, despite the cap 60being welded to the body 50, gas may still leak from the canister 40and, therefore, the canister 40 may be weighed to ensure that anadequate fill of gas remains to ensure sufficient gas through the strokeof the medical device into which the canister 40 is to be loaded. Oneapproach is to weigh the canister 40 following filling; expose thecanister 40 to elevated temperatures to raise the internal pressure toaccelerate any leakage that may be present; reweigh the canister 40 todetermine if the mass has been reduced indicating the leak; and thenextrapolate the leakage rate over the shelf life to ensure thatsufficient gas will remain in the canister 40 over the shelf life of theproduct.

Forming the body 50 and cap 60 from stainless steel may providecorrosion protection for the resulting canister 40 over its target shelflife. Galvanized steel has been used for conventional gas canisters toprovide corrosion protection, but may be inadequate for the canister 40.In particular, metallic plating, e.g., zinc, cannot be applied beforewelding the cap 60 to the body 50 since the plating would be lost at theweld, thereby compromising the corrosion protection. If additionalplating were applied to the weld, the plating may not have a uniformthickness (on each canister and between different canisters). However,it will be appreciated that any appropriate and/or desired material,such as metal, plastic, and/or composite materials, may be used insteadof stainless steel or galvanized steel.

Such variances in plating (before or after welding) may not meet therequired tolerances to ensure that the mass and/or pressure of the gaswithin the finished cylinder falls within the desired range. Stainlesssteel can be formed to higher tolerances since no such plating isneeded, thereby ensuring that the properties of the gas may beaccurately determined after filling and/or over the shelf life of thecanister.

Subsequently, during manufacturing, the canister 40 may be loaded into amedical device to provide an energy source that may be controllablyreleased to provide a desired discharge force to operate the medicaldevice. As explained above, in some embodiments, the energy source maybe pressurized CO2. For example, in some embodiments, the IOL inserter10 may be provided to the user with the canister 40 pre-loaded withinthe chamber 16 of the housing 12. Thus, in some instances, a medicaldevice pre-loaded with the canister 40 may be a disposable, single-usedevice. In some embodiments, the cap 14 may be substantially permanentlycoupled to the housing 12, e.g., by bonding with adhesive, sonicwelding, interference fit, one or more connectors, and the like (notshown) to prevent the cap 14 and canister 40 from being removed by theuser.

Alternatively, the IOL inserter 10 may be a reusable device, e.g., inwhich the user may load one or more canisters 40 successively into thehousing 12, as desired. For example, with the IOL inserter 10 shown inFIGS. 1A and 1B, the user may remove the cap 14 and load a canister 40into the chamber 16 of the main body portion 12 of the IOL inserter 10,e.g., such that the septum 67 of the cap 60 is disposed adjacent the pin34, as shown in FIG. 1A. The cap 14 may then be reconnected to the mainbody portion 12 to secure the canister 40 within the housing 12.

At any time, the actuator 30 may be activated to direct the carriage 32proximally to the proximal position shown in FIG. 1B such that the pin34 penetrates the septum 67, thereby delivering CO2 from the canister 40into one or more passages of the IOL inserter 10. Alternatively, in theembodiment shown in FIGS. 5A and 5B, the perimeter 167 b of the septum167 may tear or otherwise separate at least partially around the centralregion 167 a, thereby delivering CO2 from the canister 140. The releasedCO2 may be used to pressurize an incompressible liquid, e.g., siliconeoil, within the housing 12. The pressurized incompressible liquid may beused to deliver a lens from the lens compartment 22. The O-ring seal 36may slide along the neck region 58 and prevent CO2 from leaking into thechamber 16 or elsewhere other than the intended passages within the IOLinserter 10. The actuator 30 may then be released, allowing the carriage32 to return to the distal position shown in FIG. 1A.

In embodiments in which the lens compartment 22 defines a separate lenscartridge, the lens compartment 22 may loaded into the lens deliveryportion 20 (or may already be loaded). However, as explained above, thelens compartment 22 may be fixedly attached to the main body portion 12or form an integral portion thereof. The actuator 30 of the IOL inserter10 may be activated at any time to controllably deliver theincompressible fluid under constant pressure from the CO2, e.g.,silicone oil, to deliver the lens from the lens compartment 22. Forexample, the actuator 30 may be selectively actuated such that the flowrate of the incompressible liquid is proportional to the extent theactuator 30 is activated, e.g., to advance the lens from the lenscompartment 22 at a controlled speed, e.g., as described in theapplications incorporated by reference herein.

After the procedure, the entire IOL inserter 10 may be disposed of or,if reusable, the canister 40 may be removed, the medical device may becleaned and/or otherwise prepared for another procedure, at which timeanother canister may be loaded into the medical device.

Although the gas canisters herein have been described for use with anIOL inserter, it will be appreciated that the gas canisters may be usedwith other medical devices. For example, the gas canisters may be usedwithin a syringe device, such as that disclosed in U.S. PatentApplication Publication No. 2013/0317478, the entire disclosure of whichis expressly incorporated by reference herein. For example, such asyringe device may include a needle or other cannula that may be used todeliver viscous or other fluids contained within the device into an eye,with the gas canister providing a discharge force that may be controlledby an actuator of the syringe device to controllably deliver the fluidinto an eye. In another embodiment, the gas canisters may be used todeliver a tubular shunt or other implant (not shown) into an eye orother region of a patient's body.

It is fully contemplated that the features, components, and/or stepsdescribed with respect to one or more embodiments, methods, or Figuresmay be combined with the features, components, and/or steps describedwith respect to other embodiments, methods, or Figures of the presentdisclosure.

While the various examples described herein are susceptible to variousmodifications, and alternative forms, specific examples thereof havebeen shown in the drawings and are herein described in detail. It shouldbe understood that the scope of the present disclosure is not to belimited to the particular forms or methods disclosed, but to thecontrary, the scope of the disclosure is intended to cover allmodifications, equivalents and alternatives falling within the scope ofthe appended claims.

We claim:
 1. A canister, comprising: an elongate body comprising abarrel region defining a first diameter, an enclosed first end, and aneck region extending from the barrel region to an open second enddefining an end wall, the elongate body defining a central axisextending between the first end and the second end; and a cap attachedto the neck region to close the second end of the elongate body andenclose the cavity, the cap comprising a separable septum formed thereinthat includes a central region and a relatively-thin perimeter at leastpartially surrounding the central region for preferentially tearing ofthe perimeter to at least partially separate the central region from thecap, the cavity filled with pressurized fluid.
 2. The canister of claim1, wherein the perimeter completely surrounds the central region.
 3. Thecanister of claim 1, wherein the perimeter extends partially around thecentral region to define a preferential hinge.
 4. The canister of claim1, wherein the central region has a dome shape.
 5. The canister of claim1, wherein the cap comprises an annular portion including a closed firstend and an open second end opposite the first end, the septum formed inthe first end of the cap.
 6. The canister of claim 1, wherein the firstend of the cap further comprises an annular shoulder surrounding theperimeter region, the perimeter region having a thickness thinner thanthe thickness of the central region and the annular shoulder forpreferentially tearing of the perimeter region to at least partiallyseparate the central region from the annular shoulder.
 7. The canisterof claim 5, wherein the cap further comprises a flange extendingradially from the cap, and wherein the annular flange is secured to theend wall to enclose the cavity.
 8. The canister of claim 1, wherein: thecap comprises an annular portion including a closed first end and anopen second end opposite the first end, a flange extending radially fromthe second end of the annular portion, the septum formed in the firstend of the cap; and the first end of the annular portion of the cap isinserted into the open second end of the elongate body such that theannular portion is spaced from an interior surface of the neck regionand the septum is disposed within the neck region, the annular flangesecured to the end wall of the second end of the elongate body, therebyenclosing a cavity.
 9. The canister of claim 1, wherein the cavity isfilled with pressurized and/or at least partially liquefied gas.
 10. Thecanister of claim 1, wherein the elongate body and the cap are formedfrom stainless steel and wherein the cap is welded to the second end toenclose the cavity.
 11. A canister, comprising: an elongate bodycomprising a barrel region defining a first diameter, an enclosed firstend, and a neck region extending from the barrel region to an opensecond end defining an end wall, the elongate body defining a centralaxis extending between the first end and the second end; and a capcomprising an annular portion including a closed first end and an opensecond end, a separable septum formed in the first end of the capcomprising a central region and a relatively-thin perimeter at leastpartially surrounding the central region for preferentially tearing ofthe perimeter to at least partially separate the central region from thecap, the cap secured to the end wall of the second end of the elongatebody, thereby enclosing a cavity, the cavity filled with pressurizedand/or at least partially liquefied gas.
 12. The canister of claim 11,wherein the cap further comprises a flange extending radially from thesecond end of the annular portion of the cap, and where the annularflange is secured to the end wall to enclose the cavity.
 13. Thecanister of claim 12, wherein the first end of the annular portion ofthe cap inserted into the open second end of the elongate body such thatthe annular portion is spaced from an interior surface of the neckregion and the septum is disposed within the neck region, the annularflange secured to the end wall of the second end of the elongate body,thereby enclosing a cavity.
 14. The canister of claim 11, wherein thefirst end of the cap further comprises an annular shoulder surroundingthe perimeter region and extending inwardly from the annular portion,the perimeter region having a thickness thinner than the thickness ofthe central region and the annular shoulder for preferentially tearingof the perimeter region to at least partially separate the centralregion from the annular shoulder.
 15. A gas-actuated tool, comprising: ahousing comprising a functional portion and an actuator portionincluding a chamber; a canister within the chamber comprising anelongate body comprising an enclosed first end and an open second end, acap welded to the open second end of the elongate body and including aseptum, thereby defining an interior cavity filled with pressurized gas,the septum comprising a central region and a relatively-thin perimeterat least partially surrounding the central region; a carriage movablewithin the housing from the first position, the carriage comprising apin disposed adjacent the septum, the pin including a blunt, beveledtip; and an actuator on the actuator portion coupled to the carriagesuch that initial activation of the actuator causes the carriage to movefrom the first position to a second position such that the beveled tipof the pin applies localized force to the septum to at least partiallyseparate the septum from the cap, thereby releasing pressurized gas fromthe canister into one or more passages within the housing.